1. Field of the Invention
The present invention relates to railings made with treated lumber and metal balusters wherein the balusters are isolated from corrosion by the lumber.
2. Brief Description of the Prior Art
It has been found that an attractive fence or railing resembling a wrought iron fence can be made with hollow metal balusters mounted in holes drilled in top and bottom wooden rails. One such construction is described in our earlier patent (U.S. Pat. No. 6,394,422 to Jones et al.) incorporated by reference herein.
In recent years there has been a change in the chemicals employed for treating lumber used in an outdoor environment. Arsenic, the primary component used to preserve wood from deterioration, has been eliminated. To compensate for the lack of arsenic, the amount of copper containing chemicals impregnated into the wood has been greatly increased. The increased copper content has caused the metal balusters, when formed of aluminum, to corrode, especially at the point of contact with the wood. The problem of corrosion is increased in the outdoor environment where the components are exposed to moisture, i.e., from rain, dew and other sources.
U.S. Pat. Nos. 1,797,883, 3,810,341, 4,403,767, 4,886,245, 5,419,538, 5,474,395, 6,126,148, 6,305,670, 6,308,937, 6,311,957, and 6,394,422 are incorporated by reference herein.